TEHRAN, July 7 -- Iran said today that it had completed testing of a long-range, surface-to-surface missile that military analysts say could strike its archenemy Israel.

A Foreign Ministry spokesman, Hamid Reza Asefi, told reporters that a final test of the Shahab-3 ballistic missile was performed "a few weeks ago." State radio said it was the last test before the missile was delivered to the armed forces.

The Shahab-3, first tested in 1998, has a range of 800 miles. It is based on the North Korean Nodong-1 missile, but has been improved with Russian technology.

The United States has accused Iran of developing nuclear arms and the means to deliver them. "We have long had very serious concerns about Iranian missile programs," State Department spokesman Richard Boucher told reporters in Washington today. "We've seen Iran's efforts to develop its missile capabilities, including flight testing, as a threat to the region and a threat to U.S. interests in the region."

Iran says its nuclear program is for peaceful purposes and its missiles are only a deterrent. The head of the International Atomic Energy Agency, Mohamed ElBaradei, will visit Tehran this week to tackle concerns over Iran's nuclear program.

"They have been testing this missile for some time, so it is not an unknown. The only bad thing about it is the timing because of the ElBaradei visit," said an Asian diplomat in Tehran. "But it shows they haven't altered the schedule of their missile tests in response to external pressure."

Military analysts say Israel is within the missile's range. Iran has publicly refused to acknowledge the right of the Jewish state to exist, though officials recently said they would not oppose a two-state solution to the Israeli-Palestinian conflict if Palestinians backed it.

ElBaradei's visit Wednesday could be a key test of Iran's willingness to ease mounting international concern that it is secretly developing nuclear weapons. The head of the U.N. watchdog agency is expected to renew his call for Iran to sign an additional protocol to the nuclear Non-Proliferation Treaty that would allow inspectors to carry out more intrusive, short-notice checks of its nuclear facilities.